Determine the long-term course of artherosclerotic cardiovascular disease in Type 1 diabetes, effects and interactions of risk factors for cardiovascular disease, evolution of microalbuminuria and clinical nephropathy, development of neuropathy, development of retinopathy, development of abnormal lipid and lipoprotein levels, analyze glycemic levels, and study health care provided to patients with Type 1 diabetes in the U.S. and Canada.